California’s largest public-employee union announced Saturday that it had reached a contract agreement with Gov. Jerry Brown’s administration. If workers ratify the deal, it would bring to a close contentious negotiations that led to a strike threat and allegations of bad-faith bargaining. Service Employees International Union Local 1000 didn’t immediately release the terms of the deal, but union President Yvonne Walker said in a statement that it achieves improvements in compensation, professional development, working conditions, and health and safety. …